1. Field of the Invention
The present invention pertains to a method for removing overburden in a surface mining operation using a dragline type excavator and blast casting of the overburden, both in such a way as to reduce the excavating effort and expose a coal or other mineral seam of substantial width.
2. Background
The efficiency of large scale surface mining methods is important in order to reduce, in many instances, the time required to move overburden material away from the mineral seam sufficiently to permit mining of the mineral material, to save wear and tear on the mining equipment and reduce the overall cost of the mining operation. The volume of material mined and the competitive pricing of many minerals, such as coal, is of such magnitude that savings in excavating time and wear and tear on excavating equipment more than offsets any increased cost due to drilling and blast casting the overburden. One improved method is described and claimed in a patent application entitled: "Earth Excavation Using Blast Casting and Excavating Apparatus", filed of even date herewith in the name of Monica Cummins and assigned to the assignee of the present invention.